Stool Test Spots Most Colon Cancers

A stool test known as the fecal immunochemical test (FIT) is accurate in diagnosing most colorectal cancers, according to a meta-analysis published in the Annals of Internal Medicine.

Screening is crucial for the prevention and early detection of colorectal cancer. The American Cancer Society currently recommends that people at average risk of colorectal cancer begin being screened for colorectal cancer at the age of 50. Screening may need to begin at a much earlier age for people with a personal or family history of adenomatous polyps, FAP, HNPCC, colorectal cancer, or chronic inflammatory bowel disease.

There are several available screening strategies for colorectal cancer, including colonoscopy, sigmoidoscopy, fecal occult blood test (FOBT), and FIT. Colonoscopy is considered the gold standard in screening for colorectal cancer. The U.S. Preventive Services Task Force (USPSTF) recommends that people between ages 50 and 75 get screened by colonoscopy every 10 years or sigmoidoscopy every five years or FOBT every 1-3 years.

FOBT checks for hidden blood in the stool, which can indicate the presence of polyps. The test requires more samples and more pre-test changes to a person’s diet and medication schedule than the newer FIT.

FIT is a newer type of stool test that does not require drug or dietary restrictions on the part of the patient. Patients perform the test at home, using a kit; the process involves obtaining a stool sample and mailing it to a laboratory for testing.

Researchers conducted a meta-analysis of 19 studies evaluating the efficacy of FIT. The studies included people with no symptoms of colon cancer, most of whom were screened with colonoscopy after undergoing FIT screening.

The results of the analysis indicated that FIT detected 79 percent of colon cancers after one test. Among people who did not have colon cancer, 94 percent tested negative for the disease. In comparison, FOBT has an accuracy between 13 and 50 percent.

FIT is more expensive than FOBT, but also simpler and more accurate. Such a simple, user friendly screening test could serve to ensure that more people get screened.